Biology And Behaviour (1-2)

Question 1

absolute refractory period

Answer 1

The brief period of time following an action potential when the ion channel is unable to respond again.

Question 2

action potential

Answer 2

The electrical signal that passes along the axon and subsequently causes the release of chemicals from the terminal buttons.

Question 3

all-or-none principle

Answer 3

The principle that when a neuron fires, it fires with the same potency each time; a neuron either fires or not, although the frequency of firing can vary.

Question 4

amygdala

Answer 4

A brain structure that serves a vital role in learning to associate things with emotional responses and in processing emotional information.

Question 5

autonomic nervous system (ANS)

Answer 5

A component of the peripheral nervous system; it transmits sensory signals and motor signals between the central nervous system and the body’s glands and internal organs.

Question 6

axon

Answer 6

A long, narrow outgrowth of a neuron by which information is conducted from the cell body to the terminal buttons.

Question 7

basal ganglia

Answer 7

A system of subcortical structures that are important for the planning and production of movement.

Question 8

brain stem

Answer 8

An extension of the spinal cord; it houses structures that control functions associated with survival, such as heart rate, breathing, swallowing, vomiting, urination, and orgasm.

Question 9

Broca’s area

Answer 9

A small portion of the left frontal region of the brain, crucial for the production of language.

Question 10

cell body

Answer 10

The site in the neuron where information from thousands of other neurons is collected and integrated.

Question 11

central nervous system (CNS)

Answer 11

The brain and the spinal cord.

Question 12

cerebellum

Answer 12

A large, convoluted protuberance at the back of the brain stem; it is essential for coordinated movement and balance.

Question 13

cerebral cortex

Answer 13

The outer layer of brain tissue, which forms the convoluted surface of the brain; the site of all thoughts, perceptions, and complex behaviors.

Question 14

chromosomes

Answer 14

Structures within the cell body that are made up of DNA, segments of which comprise individual genes.

Question 15

corpus callosum

Answer 15

A massive bridge of millions of axons that connects the hemispheres of the brain and allows information to flow between them.

Question 16

dendrites

Answer 16

Branchlike extensions of the neuron that detect information from other neurons.

Question 17

dizygotic twins

Answer 17

Also called fraternal twins; twin siblings that result from two separately fertilized eggs and therefore are no more similar genetically than nontwin siblings.

Question 18

dominant gene

Answer 18

A gene that is expressed in the offspring whenever it is present.

Question 19

electroencephalography (EEG)

Answer 19

A technique for measuring electrical activity in the brain.

Question 20

endocrine system

Answer 20

A communication system that uses hormones to influence thoughts, behaviors, and actions.

Question 21

frontal lobes

Answer 21

Regions of the cerebral cortex—at the front of the brain—important for movement and higher-level psychological processes associated with the prefrontal cortex.

Question 22

functional magnetic resonance imaging (fMRI)

Answer 22

An imaging technique used to examine changes in the activity of the working human brain by measuring changes in the blood’s oxygen levels.

Question 23

gene expression

Answer 23

Whether a particular gene is turned on or off.

Question 24

genes

Answer 24

The units of heredity that help determine an organism’s characteristics.

Question 25

genotype

Answer 25

The genetic constitution of an organism, determined at the moment of conception.

Question 26

heredity

Answer 26

Transmission of characteristics from parents to offspring through genes.

Question 27

heritability

Answer 27

A statistical estimate of the extent to which variation in a trait within a population is due to genetics.

Question 28

hippocampus

Answer 28

A brain structure that is associated with the formation of memories.

Question 29

hormones

Answer 29

Chemical substances, released from endocrine glands, that travel through the bloodstream to targeted tissues; the tissues are subsequently influenced by the hormones.

Question 30

hypothalamus

Answer 30

A brain structure that is involved in the regulation of bodily functions, including body temperature, body rhythms, blood pressure, and blood glucose levels; it also influences our basic motivated behaviors.

Question 31

insula

Answer 31

The part of the cerebral cortex lying inside the lateral fissure; important for taste, pain, perception of bodily states, and empathy.

Question 32

magnetic resonance imaging (MRI)

Answer 32

A method of brain imaging that uses a powerful magnetic field to produce high-quality images of the brain.

Question 33

monozygotic twins

Answer 33

Also called identical twins; twin siblings that result from one zygote splitting in two and that therefore share the same genes.

Question 34

myelin sheath

Answer 34

A fatty material, made up of glial cells, that insulates some axons to allow for faster movement of electrical impulses along the axon.

Question 35

neurons

Answer 35

The basic units of the nervous system; cells that receive, integrate, and transmit information. They operate through electrical impulses, communicate with other neurons through chemical signals, and form neural networks.

Question 36

neurotransmitters

Answer 36

Chemical substances that transmit signals from one neuron to another.

Question 37

nodes of Ranvier

Answer 37

Small gaps of exposed axon between the segments of myelin sheath, where action potentials take place.

Question 38

occipital lobes

Answer 38

Regions of the cerebral cortex—at the back of the brain—important for vision.

Question 39

parasympathetic division

Answer 39

A division of the autonomic nervous system; it returns the body to its resting state.

Question 40

parietal lobes

Answer 40

Regions of the cerebral cortex—in front of the occipital lobes and behind the frontal lobes—important for the sense of touch and for attention to the environment.

Question 41

peripheral nervous system (PNS)

Answer 41

All nerve cells in the body that are not part of the central nervous system. The peripheral nervous system includes the somatic and autonomic nervous systems.

Question 42

phenotype

Answer 42

Observable physical characteristics, which result from both genetic and environmental influences.

Question 43

pituitary gland

Answer 43

A gland located at the base of the hypothalamus; it sends hormonal signals to other endocrine glands, controlling their release of hormones.

Question 44

plasticity

Answer 44

A property of the brain that allows it to change as a result of experience or injury.

Question 45

positron emission tomography (PET)

Answer 45

A method of brain imaging that assesses metabolic activity by using a radioactive substance injected into the bloodstream.

Question 46

prefrontal cortex

Answer 46

The frontmost portion of the frontal lobes, especially prominent in humans; important for attention, working memory, decision making, appropriate social behavior, and personality.

Question 47

receptors

Answer 47

In neurons, specialized protein molecules on the postsynaptic membrane; neurotransmitters bind to these molecules after passing across the synapse.

Question 48

recessive gene

Answer 48

A gene that is expressed only when it is matched with a similar gene from the other parent.

Question 49

relative refractory period

Answer 49

The brief period of time following action potential when a neuron’s membrane potential is more negative, or hyper-polarized, making it harder to fire again.

Question 50

resting membrane potential

Answer 50

The electrical charge of a neuron when it is not active.

Question 51

split brain

Answer 51

A condition that occurs when the corpus callosum is surgically cut and the two hemispheres of the brain do not receive information directly from each other.

Question 52

sympathetic division

Answer 52

A division of the autonomic nervous system; it prepares the body for action.

Question 53

synapse

Answer 53

The gap between the terminal buttons of a “sending” neuron and the dendrites of a “receiving” neuron, where chemical communication occurs between the neurons.

Question 54

temporal lobes

Answer 54

Regions of the cerebral cortex—below the parietal lobes and in front of the occipital lobes—important for processing auditory information, for memory, and for object and face perception.

Question 55

terminal buttons

Answer 55

At the ends of axons, small nodules that release chemical signals from the neuron into the synapse.

Question 56

thalamus

Answer 56

The gateway to the brain; it receives almost all incoming sensory information before that information reaches the cortex.

Question 57

transcranial magnetic stimulation (TMS)

Answer 57

The use of strong magnets to briefly interrupt normal brain activity as a way to study brain regions.

Question 58

reuptake

Answer 58

The process whereby a neurotransmitter is taken back into the presynaptic terminal buttons, thereby stopping its activity.

Question 59

somatic nervous system (SNS)

Answer 59

A component of the peripheral nervous system; it transmits sensory signals and motor signals between the central nervous system and the skin, muscles, and joints.